1. Technical Field
The present invention relates to a touch panel.
2. Description of the Related Art
In accordance with the growth of computers using a digital technology, devices assisting computers have also been developed, and personal computers, portable transmitters and other personal information processors execute processing of text and graphics using a variety of input devices such as a keyboard and a mouse.
While the rapid advancement of an information-oriented society has been widening the use of computers more and more, it is difficult to efficiently operate products using only a keyboard and mouse currently serving as an input device. Therefore, the necessity for a device that is simple, has minimum malfunction, and is capable of easily inputting information has increased.
In addition, current techniques for input devices have progressed toward techniques related to high reliability, durability, innovation, designing and processing beyond the level of satisfying general functions. To this end, a touch panel has been developed as an input device capable of inputting information such as text, graphics, or the like.
This touch panel is mounted on a display surface of an image display device such as an electronic organizer, a flat panel display device including a liquid crystal display (LCD) device, a plasma display panel (PDP), an electroluminescence (El) element, or the like, or a cathode ray tube (CRT) to thereby be used to allow a user to select desired information while viewing the image display device.
Meanwhile, a mutual capacitive type touch panel obtains a coordinate of a contacting point by measuring change in a capacitance between two kinds of electrode patterns and an input unit, wherein the capacitance which is changed by an actual user shows a value higher or lower than an actual value due to a parasitic capacitance which may be generated between short-distance electric field lines at an undesirable position while a capacitance change is generated by the above-mentioned electrode patterns, such that reliability of touch recognition on a touch screen is decreased. In addition, as described in the following US Patent Laid-Open Publication No. 20110242050, the touch panel has a problem that cannot but be solved by adding separate component or adding a circuit design in order to remove the parasitic capacitance which cannot but be generated at the undesirable portion.